It has a more refined auto-focus system so it can acquire the primary subject a little faster.

ENGADGET: The Engadget Interview: Steve Heiner, General Manager, Digital SLR Systems, Nikon

To support the ample sensitivity of the new camera's sensor, the EOS 6D camera's Auto Focus (AF) system includes a newly-developed 11-point AF sensor featuring a high-precision center cross-type point with an exceptional EV -3 sensitivity rating for accurate focusing even in extremely low-light conditions.

ENGADGET: Canon unveils EOS 6D DSLR: full frame sensor and WiFi for $2,099 in December